After the oil well
penetrating through the oil layer and the bottom water layer, the well completions
are implemented in oil and water layer, and the two layers were seperated by a
packer. When the well opens for production, oil is produced above the oil-water
packer and is taken out from the air. While the water is collected and
extracted from the oil pipe bellow the packer. Compared with the conventional
well completion method, this method is equivalent to adding a sink in the water
area. The water draining at this water point changes the stratigraphic distribution，especially the area near
well, and thus changes the flow of fluid in the near well field. Considering
the difference in viscosity and thickness of oil and water, the draining rate
can be properly adjusted according to oil extraction rate. The pressure drop
generated in the water zone can balance the pressure drop caused by the oil
production, thus making the oil-water packerbecome an oil-water flow surface
and keep in a stable suitation. Under the same conditions, the DWS (Dual Well
Completion Technology) method can increase the oil production rate by 5 times
and the recovery factor by 70 percentage points.
